Variable differential speed-gear.



E. DRAULLBTTE.

VARIABLE DIFFERENTIAL SPEED GEAR.

APPLIOATION FILED MAR. 7, 1908.

EDMON'D-DRAULLETTE, 0F PARIS', FRANCE.

VARIABLE DIFFERENTIAL SPEED-GrEAIlthl i,oip5,4isi.

Specification of Letters Patent. Patented Jan. 23, 1912.

4Application filed March 7, 1908. Serial No. 419,826.

To all whom it may concern:

Be it known that I, EDMOND DRAULLETTE, a citizen of theFrench Republic, and resident of Paris, France, have invented `new and useful Improvements in Variable Differential Speed-Gear, of which the follow- 'ing is a full, clear, and exact description.

rllhe present invent-ion relates to the improvement in variable s'peed devices vbased on the principle of a differential satellite gear. y n The description of the invention is given hereinafter with reference to the accom-- panying drawing, of which the figure represents a section through the apparatus taken through the axis of the main shaft and of the secondary or auxiliary shaft.

The progressive variable speed gear is essentially composed of twoprincipal parts, the speed-combination of which forms 'the object of the present invention: 1.--A differential gear with straight pinions. 2.-A set of extensible pulleys which serve for the purpose of varying the relative speed ofthe outer toothed ring and of the satellites.

The main-shaft l receives a direct or conveniently reduced motion, as shown by way ofexaniple in the drawing, from the angular pinion 2 and through the wheel 3 which. is keyed upon the shaft 1. There are further keyed upon said shaft l the eXtensible driv'- ing pulleys l and 5 to which correspond two other extensible pulleys 6 and 7 actuated by chains, cables or any other suitable means for transmission and revolving in the same direction as the main-shaft. The pulley 6 with the annular part 8, the pulley 7 and the central pinion l0 are keyed upon special sleeves which are loosely mounted upon one and the same lshaft 25 which is driven from vthe central pinion 10.

Supposing the motion originally to start I from the position of the wheels represented in the drawings; the large drivingpulley 4 operates the small pulley 6 which has, keyed upon its hub, the outer ring 8 of the differential gear; the small driving pulley operates vthe large pulley 7 which takes lalong in its revolving motionthe satellite pinions 9; and as in the case presented the angular speeds of the satellites 9 and of the ring 8 are unequal owing to the diameters of the driven pulleys; the'central pinion 10 will be moved tained, upon the inner shaft being determined by calculation.

The position on the drawing is the position of high back speed. When the pulley 6 operated fromthe pulley 4 augments its diameter, the pulley 7 operated from the pulley 5 will diminish its diameter., The speed of the outer ring 8 will be reduced while the speed of the pinio-ns 9 will increase and the difference of speed of the two parts 8 and 9 from a maximum, which for a motorcar will be the highback speed, for example, will become Zero after having passed through such a value that the movement obtained upon the central pinion 10 will be equal to zero and then lwill gradually increase as a forward motion. Thus for this pinion l0 the following phases are obtained: 1.-High back speed diminishing to zero. 2.-Irogressive forward -motion up to the desired maximum, obtained when the satellites and the ring will revolve at the same speed, that is to say, when the four pulleys `are equal. Iior obtaining the variation of diameters of corresponding extensible pulleys, that isI to say -the variation'r of speed in forward 'and in backward direction and the stopping of the car, any suitable meansl operated by hand or foot may be used vas well as any suitable device which is automatically actuated by the engine. lhe apparatus is applicablein all industries where explosion engines are employed, such as cranes, rollingbridges, tool-engines, lifts, looms etc.

In the drawing the device is shown as specially adapted for a motorcar; the motor being placed at the front end of the frame and connected with the variable speed gear through the shaft whichoperates the pinion 2. The central pinion 10, by its sleeve operates in the usual manner another dierensleeves loosely mounted upon the said shaft;

two other eXtensible pulleys, a planetary gearing between the last mentioned pulleys and on the secondary shaft, and connecting means between each pair of eXtensible pulleys, the said planetary. gearing being composed of three parts, the annular part connected to one of the pulleys and the satellitesconnected direotly-to the fixed cheek of the other extensible pulley, and the central pinion transmitting the movement, whereby f the final or transmitted movement may be changed in speed or in direction or caused to cease by varying the relative speeds of the annular part and of the satellites; the said pulleys, annular part and central pinion being keyed upon the said special sleeves loosely mounted upon the secondary shaft which is driven from the central pinion; substantially as described' and for the purpose set forth.

EDMOND DRAULLETTE. Witnesses: A

PAUL RUPUY, Louis ALLAIN. 

